Let's go through this simple example of jQuery to browse an array of JavaScript objects.

var json = [
 {"id":"1","text":"paris"},
 {"id":"2","text":"marseille"},
 {"id":"3", "text":"Lille"},
 {"id":"4","text":"Metz"},
 {"id":"5","text":"renne"}
]; 

$.each(json, function(i, obj) {
 alert(obj.text); 
}); 

The execution of this example runs correctly and the cities are displayed in an alert box. A common problem with declaring a string JSON with a single or double quottes.

var json = '[{"id":"1","city":"paris"},{"id":"2","city":"marseille"},
{"id":"3","city":"lille"},{"id":"4","city":"metz"},
{"id":"5","city": "reindeer"}]'; 
 
$.each(json, function(i, obj) {
 alert(obj.city); 
}); 

Chrome browser displays this error in console:

Uncaught TypeError: Cannot use 'in' operator to search for ... 
in [{"id":"1","ville":"paris"}... 

The ideal solution is to convert JSON to a JavaScript object with the JSON.parse() function or the jQuery function $.parseJSON.

$.each(JSON.parse(json), function(i, obj) {
 alert(obj.ville); 
}); 

//ou

$.each($.parseJSON(json), function(i, obj) {
 alert(obj.city); 
}); 

JSON example and the JavaScript loop for

The following example shows how to iterate through a JSON object using the JavaScript for loop.

 
 
< head> 
 < meta charset="utf-8"> 
 < title> Example of the javascript for and JSON loop 
 < script src="https://code.jquery.com/jquery-1.10.2.js"> 
 
< body> 

< script> 
$(function() {

var data = [
 {"id":"1","name":"One"},
 {"id":"2","name":"Two"},
 {"id":"3","name":"Three"},
 {"id":"4","name":"Four"},
 {"id":"5","name":"Five"}
]; 
 
var data_length = data.length; 
for (var i = 0; i < data_length; i++) {
 alert(data[i]["id"] + " " + data[i]["name"]); 
}
}); 
 
 
 

Resources:
jQuery each() method
How to iterate json data in jquery